High-transmittance lens and preparation process thereof

Abstract

This invention relates to the field of lens materials technology, specifically a high-transmittance lens and its manufacturing process, comprising the following components: polycarbonate, a modified polycarbonate-polymethyl methacrylate composite, an antioxidant, and a lubricant. This invention introduces a benzotriazole functional component into polymethyl methacrylate, endowing it with UV protection; and introduces a hindered phenol functional component into polycarbonate, endowing it with antioxidant protection. The two are covalently integrated into the same composite, forming a synergistic protection system against photo-oxidative degradation. Simultaneously, an alicyclic isophorone diisocyanate is used to bridge the two modified polymers, acting as a compatibilizer in the blend, inhibiting microphase separation, maintaining optical homogeneity, and ensuring the long-term resistance to yellowing of the bridging structure itself.

Description

Technical Field

[0001] This invention relates to the field of lens material technology, specifically a high-transmittance lens and its manufacturing process. Background Technology

[0002] Polycarbonate (PC) is widely used in optical lenses, automotive optical components, outdoor lighting covers, and solar concentrator systems due to its excellent optical transparency and outstanding impact resistance. Patent publication number CN116675943A discloses a high-temperature resistant and aging-resistant optical lens material and its preparation method. It employs a ternary blend system of polycarbonate, polymethyl methacrylate, and modified silicone resin, and through a complex pre-modification process, improves the material's high-temperature resistance and resistance to thermo-oxidative aging to a certain extent.

[0003] However, in practical applications such as automotive camera lenses, outdoor LED lighting lenses, and solar concentrator lenses, optical lenses are subjected to the combined effects of solar irradiation (UV band 290–400 nm) and device operating heat radiation (lens surface temperature can reach 80–120°C) for extended periods. This optical lens material primarily optimizes for a single thermo-oxidative aging path, failing to effectively address the photo-oxidative degradation problem of polycarbonate under the long-term combined effects of UV light and heat radiation. Under the long-term combined effects of UV light and heat radiation, polycarbonate is prone to photo-oxidative degradation, generating colored products, causing yellowing, a continuous decrease in light transmittance, and shortening product lifespan. To address this type of photo-oxidative degradation, small-molecule UV absorbers and hindered phenolic antioxidants are typically added directly. However, small-molecule additives have significant limitations under long-term thermo-photosynthetic aging conditions: their low molecular weight makes them prone to migration and volatilization to the material surface under long-term thermo-photosynthetic effects, leading to continuous loss of functional components and a significant decrease in protective efficacy over time, making it difficult to meet the practical requirements for long-term stable protection. In addition, although both polycarbonate and polymethyl methacrylate are optically transparent polymers, their thermodynamic compatibility is limited. Direct blending can easily lead to microphase separation, resulting in problems such as increased haze and decreased light transmittance in the blend after molding. Summary of the Invention

[0004] (1) Technical problems to be solved

[0005] The purpose of this invention is to provide a lens with high light transmittance and its manufacturing process, so as to solve the problem that the light transmittance of polycarbonate will continue to decrease due to photo-oxidative degradation under the long-term synergistic effect of ultraviolet light and thermal radiation.

[0006] (2) Technical solution

[0007] To achieve the above objectives, in one aspect, the present invention provides a lens with high light transmittance, comprising the following components in parts by weight: 75-85 parts polycarbonate, 12-22 parts modified polycarbonate-polymethyl methacrylate composite, 0.08-0.20 parts antioxidant, and 0.05-0.15 parts lubricant;

[0008] The modified polycarbonate-polymethyl methacrylate composite is prepared by bridging and coupling modified polymethyl methacrylate and modified polycarbonate with isophorone diisocyanate; wherein the modified polymethyl methacrylate is prepared by copolymerizing methyl methacrylate with 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole, and the modified polycarbonate is prepared by esterification of low molecular weight polycarbonate with 3,5-di-tert-butyl-4-hydroxybenzoate.

[0009] Furthermore, the antioxidant is a compound of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 2:1 to 3:1; the lubricant is pentaerythritol stearate.

[0010] Furthermore, the preparation method of the modified polymethyl methacrylate includes the following steps:

[0011] S11. Methyl methacrylate and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole are added to a reaction vessel; toluene is then added as a solvent; high-purity nitrogen is introduced to remove dissolved oxygen, resulting in a monomer mixture.

[0012] S12. Under nitrogen protection, mercaptoethanol is added to the monomer mixture; then the initiator azobisisobutyronitrile is added and stirred until completely dissolved; under nitrogen protection, the temperature is increased to react; stirring is maintained during the reaction; after the reaction is completed, the temperature is lowered to obtain a polymer solution;

[0013] S13. Add the polymer solution to methanol and stir to precipitate the polymer; filter and collect the precipitate; wash the precipitate with methanol to remove unreacted monomers, mercaptoethanol residue and oligomers; dry and pulverize the washed precipitate to obtain modified polymethyl methacrylate.

[0014] Further, the mass ratio of methyl methacrylate to 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole is 93:7; the amount of azobisisobutyronitrile is 0.8% of the total mass of methyl methacrylate and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole; and the amount of mercaptoethanol is 1.5% of the total mass of methyl methacrylate and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole.

[0015] Furthermore, the preparation method of the modified polycarbonate includes the following steps:

[0016] S21. Dry the low molecular weight polycarbonate to obtain dried polycarbonate; dry 3,5-di-tert-butyl-4-hydroxybenzoic acid to obtain dried 3,5-di-tert-butyl-4-hydroxybenzoic acid; dissolve the dried polycarbonate in dichloromethane to obtain a mixed solution;

[0017] S22. Add dry 3,5-di-tert-butyl-4-hydroxybenzoic acid to the mixed solution, then add 4-dimethylaminopyridine as a catalyst, stir to dissolve, and finally add dicyclohexylcarbodiimide as a dehydrating agent; under nitrogen protection, stir the reaction to obtain a suspension;

[0018] S23. After the reaction is complete, filter the suspension to remove the byproduct dicyclohexylurea precipitate; add the obtained filtrate to methanol and stir to precipitate the product; filter and collect the solid precipitate, wash it with methanol; dry and pulverize the washed solid precipitate to obtain modified polycarbonate.

[0019] Further, the number average molecular weight of the low molecular weight polycarbonate is 3000; the amount of 3,5-di-tert-butyl-4-hydroxybenzoic acid is 7.5% to 8.5% of the mass of the low molecular weight polycarbonate; the amount of 4-dimethylaminopyridine is 0.55% to 0.65% of the mass of the low molecular weight polycarbonate; and the amount of dicyclohexylcarbodiimide is 7.0% to 8.0% of the mass of the low molecular weight polycarbonate.

[0020] Furthermore, the preparation method of the modified polycarbonate-polymethyl methacrylate composite includes the following steps:

[0021] S31. Add modified polymethyl methacrylate and modified polycarbonate to a dry reaction vessel, then add anhydrous tetrahydrofuran, and stir the reaction under nitrogen protection to fully dissolve the polymer and obtain polymer mixed solution A.

[0022] S32. Dibutyltin dilaurate is added to polymer mixture A as a catalyst and stirred under nitrogen protection to obtain polymer mixture B; isophorone diisocyanate is dissolved in anhydrous tetrahydrofuran to obtain dilute solution A; under nitrogen protection and continuous stirring, dilute solution A is slowly added dropwise to polymer mixture B using a syringe; after the addition is complete, the temperature is raised and the reaction is carried out under nitrogen protection with stirring to obtain polymer mixture C;

[0023] S33. After cooling, slowly pour the polymer mixture C into a mixed solvent of hexane and diethyl ether while stirring, and filter to obtain flocculent solid A; wash flocculent solid A with hexane; dry and pulverize the washed flocculent solid A to obtain a modified polycarbonate-polymethyl methacrylate composite.

[0024] Furthermore, the mass ratio of the modified polymethyl methacrylate to the modified polycarbonate is 2:1; the amount of isophorone diisocyanate added accounts for 1.5% of the total mass of the modified polymethyl methacrylate and the modified polycarbonate.

[0025] On the other hand, based on the same inventive concept, the present invention also provides a manufacturing process for a high-transmittance lens, applicable to the aforementioned high-transmittance lens, comprising the following steps:

[0026] S1. Raw material drying: Dry the polycarbonate and the modified polycarbonate-polymethyl methacrylate composite separately;

[0027] S2. Premixing: The dried polycarbonate, the dried modified polycarbonate-polymethyl methacrylate composite, the antioxidant, and the lubricant are sequentially added into a high-speed mixer and mixed to obtain a premix.

[0028] S3. Melt blending and granulation: The premixed material is fed into a twin-screw extruder for granulation to obtain granules;

[0029] S4. Injection molding: The obtained granules are placed in an injection molding machine, melted and injected into a lens mold, cooled and shaped to obtain a lens with high light transmittance.

[0030] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0031] 1. This invention integrates two types of functional components into the same composite via covalent bonds: first, a benzotriazole-based UV-protective component is introduced into polymethyl methacrylate (PMMA), endowing it with long-lasting UV protection; second, a hindered phenolic antioxidant component is introduced into polycarbonate, endowing it with long-lasting inhibition of thermal oxidative degradation. Unlike directly adding small-molecule functional agents, this invention fixes the functional components in the polymer system through covalent anchoring, effectively inhibiting their migration and loss under long-term thermal-photoaging conditions, ensuring stable protective efficacy throughout the entire service life, and constructing a long-lasting synergistic protection system.

[0032] 2. To address the problem of poor compatibility and increased haze when polycarbonate and polymethyl methacrylate are directly blended, this invention introduces cross-linking nodes between the two modified polymers using alicyclic isophorone diisocyanate, forming a partially coupled blend system. This effectively suppresses microphase separation and maintains the optical uniformity of the material. This partial coupling method maintains compatibility while preserving the necessary fluidity of the system during melt processing. Furthermore, the alicyclic isophorone diisocyanate itself has good resistance to yellowing, further ensuring the long-term light transmission stability of the lens. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the fabrication process of a high-transmittance lens according to the present invention.

[0034] Figure 2 This is a physical image of a high-transmittance lens according to the present invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1: This example discloses a lens with high light transmittance, comprising the following components in parts by weight: 80 parts polycarbonate, 17 parts modified polycarbonate-polymethyl methacrylate composite, 0.14 parts antioxidant, and 0.10 parts lubricant;

[0037] The modified polycarbonate-polymethyl methacrylate composite is prepared by bridging and coupling modified polymethyl methacrylate and modified polycarbonate with isophorone diisocyanate; wherein the modified polymethyl methacrylate is prepared by copolymerizing methyl methacrylate with 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole, and the modified polycarbonate is prepared by esterification of low molecular weight polycarbonate with 3,5-di-tert-butyl-4-hydroxybenzoate.

[0038] The antioxidant is a compound of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 2:1; the lubricant is pentaerythritol stearate.

[0039] The method for preparing the modified polymethyl methacrylate includes the following steps:

[0040] S11. Add 93g of methyl methacrylate and 7g of 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole to a 500mL reaction vessel; then add 300g of toluene as a solvent; bubble high-purity nitrogen gas for 30min to remove dissolved oxygen and obtain a monomer mixture.

[0041] S12. Under nitrogen protection, 1.5 g of mercaptoethanol was added to the monomer mixture; after stirring evenly, 0.8 g of the initiator azobisisobutyronitrile was added and stirred until completely dissolved; under nitrogen protection, the temperature was raised to 75 °C and the reaction was maintained for 7 h; stirring was carried out during the reaction at a speed of 150~200 r / min; after the reaction was completed, the temperature was lowered to room temperature to obtain the polymer solution.

[0042] S13. Add the polymer solution to 3000 mL of methanol and stir to precipitate the polymer; filter and collect the precipitate; wash the precipitate three times with methanol (500 mL each time) to remove unreacted monomers, mercaptoethanol residue and oligomers; dry the washed precipitate at 60 °C to constant weight; pulverize after drying to obtain modified polymethyl methacrylate.

[0043] The method for preparing the modified polycarbonate includes the following steps:

[0044] S21. Low molecular weight polycarbonate was dried at 100℃ for 4 hours to obtain dried polycarbonate; 3,5-di-tert-butyl-4-hydroxybenzoic acid was dried at 60℃ for 2 hours to obtain dried 3,5-di-tert-butyl-4-hydroxybenzoic acid; 50g of dried polycarbonate was dissolved in 400mL of dichloromethane to obtain a mixed solution;

[0045] S22. Add 4.18 g of dried 3,5-di-tert-butyl-4-hydroxybenzoic acid to the mixed solution, then add 0.31 g of 4-dimethylaminopyridine as a catalyst, stir to dissolve, and finally add 3.79 g of dicyclohexylcarbodiimide as a dehydrating agent; under nitrogen protection, stir and react at room temperature for 18 h to obtain a suspension;

[0046] S23. After the reaction is complete, filter the suspension to remove the byproduct dicyclohexylurea precipitate; add the obtained filtrate to 1500 mL of methanol and stir to precipitate the product; filter and collect the solid precipitate, wash it three times with methanol (300 mL each time); dry the washed solid precipitate at 55 °C to constant weight; after drying, pulverize to obtain modified polycarbonate.

[0047] The number average molecular weight of the low molecular weight polycarbonate is 3000; the amount of 3,5-di-tert-butyl-4-hydroxybenzoic acid is 7.5% to 8.5% of the mass of the low molecular weight polycarbonate; the amount of 4-dimethylaminopyridine is 0.55% to 0.65% of the mass of the low molecular weight polycarbonate; and the amount of dicyclohexylcarbodiimide is 7.0% to 8.0% of the mass of the low molecular weight polycarbonate.

[0048] The preparation method of the modified polycarbonate-polymethyl methacrylate composite includes the following steps:

[0049] S31. Add 26.7g of modified polymethyl methacrylate and 13.3g of modified polycarbonate to a dry reaction vessel, then add 400mL of anhydrous tetrahydrofuran, and stir at 40°C for 1h under nitrogen protection to fully dissolve the polymer and obtain polymer mixed solution A.

[0050] S32. Add 0.03 g of dibutyltin dilaurate as a catalyst to polymer mixture solution A, and stir for 10 min under nitrogen protection to obtain polymer mixture solution B; separately dissolve 0.60 g of isophorone diisocyanate in 10 mL of anhydrous tetrahydrofuran to obtain dilute solution A; under nitrogen protection and continuous stirring, slowly add dilute solution A dropwise to polymer mixture solution B using a syringe, controlling the addition time at 30~40 min; after the addition is complete, raise the temperature to 65℃, and keep the reaction at this temperature under nitrogen protection with stirring for 10 h, maintaining the stirring speed at 100~150 r / min to obtain polymer mixture solution C;

[0051] S33. After cooling to room temperature, slowly pour the polymer mixture C into 3000 mL of a 3:1 mixture of n-hexane and diethyl ether while stirring. Filter to obtain flocculent solid A. Wash flocculent solid A twice with n-hexane (500 mL each time). Dry the washed flocculent solid A at 60 °C to constant weight. After drying, pulverize and pass through an 80-mesh sieve to obtain the modified polycarbonate-polymethyl methacrylate composite.

[0052] The manufacturing process of the high-transmittance lens includes the following steps:

[0053] S1. Raw material drying: Polycarbonate and modified polycarbonate-polymethyl methacrylate composite are dried at 100~120℃ for 3~5h respectively;

[0054] S2. Premixing: The dried polycarbonate, the dried modified polycarbonate-polymethyl methacrylate composite, the antioxidant, and the lubricant are sequentially added into a high-speed mixer and mixed at 300~500 r / min for 5~10 min at room temperature to obtain the premix.

[0055] S3. Melt blending and granulation: The premixed material is fed into a twin-screw extruder, melted, sheared, blended, and then extruded and granulated to obtain granules;

[0056] S4. Injection Molding: The obtained granules are placed in an injection molding machine, melted, and injected into a lens mold. After cooling and molding, a lens with high light transmittance is obtained.

[0057] It should be noted that, as Figure 1 This is a flowchart illustrating the fabrication process of the high-transmittance lens of the present invention; as shown. Figure 2 This is a physical image of the high-transmittance lens of the present invention.

[0058] It should be noted that the process parameters of the twin-screw extruder are as follows: Zone 1 temperature 220~240℃, Zone 2 temperature 240~260℃, Zone 3 temperature 260~270℃, Zone 4 temperature 260~270℃, Die head temperature 250~260℃, Screw speed 200~300r / min, Feed speed 15~25r / min, Vacuum degree ≤-0.08MPa; the injection molding process parameters are as follows: Barrel temperature 250~280℃, Mold temperature 80~100℃, Injection pressure 80~120MPa, Holding pressure 60~80MPa, Cooling time 20~40 seconds.

[0059] Example 2: This example is based on Example 1, but differs from Example 1 in that it discloses a lens with high light transmittance, comprising the following components in parts by weight: 75 parts polycarbonate, 12 parts modified polycarbonate-polymethyl methacrylate composite, 0.08 parts antioxidant, and 0.05 parts lubricant;

[0060] The antioxidant is a mixture of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 2:1. Other components and preparation methods are the same as in Example 1.

[0061] Example 3: This example is based on Example 1, but differs from Example 1 in that it discloses a lens with high light transmittance, comprising the following components in parts by weight: 85 parts polycarbonate, 22 parts modified polycarbonate-polymethyl methacrylate composite, 0.20 parts antioxidant, and 0.15 parts lubricant;

[0062] The antioxidant is a mixture of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 2:1. Other components and preparation methods are the same as in Example 1.

[0063] Example 4: This example is based on Example 1, but differs from Example 1 in that it discloses a lens with high light transmittance, comprising the following components in parts by weight: 80 parts polycarbonate, 17 parts modified polycarbonate-polymethyl methacrylate composite, 0.14 parts antioxidant, and 0.10 parts lubricant;

[0064] The antioxidant is a mixture of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 3:1. Other components and preparation methods are the same as in Example 1.

[0065] Comparative Example 1: This comparative example is based on Example 1, but differs from Example 1 in that unmodified polymethyl methacrylate is used instead of modified polymethyl methacrylate.

[0066] The other components and preparation methods are the same as in Example 1.

[0067] Comparative Example 2: This comparative example is based on Example 1, but differs from Example 1 in that unmodified polycarbonate is used instead of modified polycarbonate.

[0068] The other components and preparation methods are the same as in Example 1.

[0069] Comparative Example 3: This comparative example is based on Example 1, but differs from Example 1 in that the modified polycarbonate-polymethyl methacrylate composite described in this comparative example is made by replacing the modified polymethyl methacrylate and modified polycarbonate with unmodified polymethyl methacrylate and unmodified polycarbonate.

[0070] The other components and preparation methods are the same as in Example 1.

[0071] Comparative Example 4: This comparative example is based on Example 1, but differs from Example 1 in that the modified polycarbonate-polymethyl methacrylate composite described in this comparative example is not modified with isophorone diisocyanate.

[0072] The preparation method of the modified polycarbonate-polymethyl methacrylate composite includes the following steps:

[0073] 26.7 g of modified polymethyl methacrylate and 13.3 g of modified polycarbonate were added to a dry reaction vessel, followed by 400 mL of anhydrous tetrahydrofuran. The mixture was stirred at 40 °C for 1 h under nitrogen protection. The dissolved solution was slowly poured into 3000 mL of a 3:1 mixture of n-hexane and diethyl ether while stirring. The mixture was filtered to obtain flocculent solid B. Flocculent solid B was washed twice with n-hexane (500 mL each time). The washed flocculent solid B was dried at 60 °C to constant weight. After drying, the solid was pulverized and passed through an 80-mesh sieve to obtain the modified polycarbonate-polymethyl methacrylate composite.

[0074] The other components and preparation methods are the same as in Example 1.

[0075] Comparative Example 5: This comparative example is based on Example 1, but differs from Example 1 in that the modified polycarbonate-polymethyl methacrylate composite described in this comparative example does not contain modified polymethyl methacrylate.

[0076] The preparation method of the modified polycarbonate-polymethyl methacrylate composite includes the following steps:

[0077] 13.3 g of modified polycarbonate was added to a dry reaction vessel, followed by 260 mL of anhydrous tetrahydrofuran. The mixture was stirred at 40 °C for 1 h under nitrogen protection. Separately, 0.20 g of isophorone diisocyanate was dissolved in 5 mL of anhydrous tetrahydrofuran to obtain dilute solution B. Under nitrogen protection and continuous stirring, dilute solution B was slowly added dropwise to the polymer solution using a syringe, with the addition time controlled at 30-40 min. After the addition was complete, the temperature was raised to 65 °C, and the reaction was maintained at this temperature and stirred for 10 h under nitrogen protection. After cooling to room temperature, the reaction solution was slowly poured into 2000 mL of a 3:1 mixture of n-hexane and diethyl ether, stirring continuously. The mixture was filtered to obtain flocculent solid C. Flocculent solid C was washed twice with n-hexane (250 mL each time). The washed flocculent solid C was dried at 60 °C to constant weight. After drying, it was pulverized and passed through an 80-mesh sieve to obtain the modified polycarbonate-polymethyl methacrylate composite.

[0078] The other components and preparation methods are the same as in Example 1.

[0079] Comparative Example 6: This comparative example is based on Example 1, but differs from Example 1 in that the modified polycarbonate-polymethyl methacrylate composite described in this comparative example does not contain modified polycarbonate.

[0080] The preparation method of the modified polycarbonate-polymethyl methacrylate composite includes the following steps:

[0081] 26.7 g of modified polymethyl methacrylate was added to a dry reaction vessel, followed by 260 mL of anhydrous tetrahydrofuran. The mixture was stirred at 40 °C for 1 h under nitrogen protection. Separately, 0.40 g of isophorone diisocyanate was dissolved in 8 mL of anhydrous tetrahydrofuran to obtain a dilute solution C. Under nitrogen protection and continuous stirring, the dilute solution C was slowly added dropwise to the polymer solution using a syringe, with the addition time controlled at 30-40 min. After the addition was complete, the temperature was raised to 65 °C, and the reaction was maintained at this temperature and stirred for 10 h under nitrogen protection. After cooling to room temperature, the reaction solution was slowly poured into 2200 mL of a 3:1 mixture of n-hexane and diethyl ether, stirring continuously. The mixture was filtered to obtain flocculent solid D. The flocculent solid D was washed twice with n-hexane (400 mL each time). The washed flocculent solid D was dried at 60 °C to constant weight. After drying, it was pulverized and passed through an 80-mesh sieve to obtain the modified polycarbonate-polymethyl methacrylate composite.

[0082] The other components and preparation methods are the same as in Example 1.

[0083] Comparative Example 7: This comparative example is based on Example 1, but differs from Example 1 in that it does not add the modified polycarbonate-polymethyl methacrylate composite, but instead uses an equal amount of polycarbonate.

[0084] The other components and preparation methods are the same as in Example 1.

[0085] Comparative Example 8: This comparative example is based on Example 1, but unlike Example 1, this comparative example does not contain octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0086] The other components and preparation methods are the same as in Example 1.

[0087] Comparative Example 9: This comparative example is based on Example 1, but unlike Example 1, this comparative example does not contain tris(2,4-di-tert-butylphenyl) phosphite.

[0088] The other components and preparation methods are the same as in Example 1.

[0089] Comparative Example 10: This comparative example is based on Example 1, but unlike Example 1, it does not contain octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate or tris(2,4-di-tert-butylphenyl)phosphite.

[0090] The other components and preparation methods are the same as in Example 1.

[0091] Comparative Example 11: This comparative example differs from Example 1 in that it uses a physical blend of 11.3 parts of unmodified polymethyl methacrylate and 5.7 parts of unmodified polycarbonate instead of the modified polycarbonate-polymethyl methacrylate composite, and additionally adds 0.22 parts of 2-(2-hydroxy-5-methylphenyl)benzotriazole and 0.35 parts of 3,5-di-tert-butyl-4-hydroxybenzoic acid.

[0092] The other components and preparation methods are the same as in Example 1.

[0093] Experimental verification:

[0094] Experiment 1: Initial Optical Performance Test

[0095] Referring to GB / T 2410-2008 "Determination of transmittance and haze of transparent plastics", a transmittance / haze tester was used to test lens samples with a thickness of 2 mm at room temperature. Five parallel samples were tested in each group, and the average value was taken.

[0096] Experiment 2: Ultraviolet-thermal radiation synergistic aging performance test

[0097] Referring to GB / T 16422.2-2022 "Laboratory Light Source Exposure Test Methods for Plastics - Part 2: Xenon Arc Lamp", a xenon lamp aging test chamber was used, with an irradiation intensity of 0.55 W / m²@340 nm, a black standard temperature of 100℃, and continuous irradiation for 1000 h. Initial transmittance and initial yellow index (YI0) were tested before aging, with the yellow index determined according to ASTM E313-20. During the aging process, parallel samples from the same batch were taken every 200 h to test transmittance and yellow index (YI) to monitor performance changes. The final transmittance retention rate was calculated as "transmittance after aging / initial transmittance × 100%", and the final yellow index (YI) was the measured value at 1000 h. Five parallel samples were tested in each group, and the average value was taken.

[0098] Table 1 Performance Test Results:

[0099]

[0100] As shown in Table 1, Examples 1-4 outperformed the comparative examples in all indicators, including initial transmittance, haze, transmittance retention after long-term aging, and yellow index. Regarding initial optical performance, the isophorone diisocyanate bridging effectively suppressed microphase separation, and the haze of Examples 1-4 was lower than that of Comparative Example 4, indicating that the bridging treatment plays a crucial role in maintaining initial optical uniformity. Regarding long-term aging performance, the covalent integration of the two functional components is the core of ensuring long-term stable protective efficacy. Compared with Comparative Example 11, Examples 1-4 exhibited superior transmittance retention and anti-yellowing ability after long-term aging, demonstrating that the covalent anchoring strategy has a significant long-term protective advantage over the direct addition scheme. These results indicate that the present invention enhances the long-term stability of the lens under UV-thermal synergistic aging without sacrificing initial optical performance, verifying the scientific validity and practicality of the invention.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-transmittance lens, characterized in that, It includes the following components in parts by weight: 75-85 parts polycarbonate, 12-22 parts modified polycarbonate-polymethyl methacrylate composite, 0.08-0.20 parts antioxidant, and 0.05-0.15 parts lubricant; The modified polycarbonate-polymethyl methacrylate composite is prepared by bridging and coupling modified polymethyl methacrylate and modified polycarbonate with isophorone diisocyanate; wherein the modified polymethyl methacrylate is prepared by copolymerizing methyl methacrylate with 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole, and the modified polycarbonate is prepared by esterification of low molecular weight polycarbonate with 3,5-di-tert-butyl-4-hydroxybenzoate.

2. The high-transmittance lens according to claim 1, characterized in that, The antioxidant is a compound of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 2:1 to 3:1; the lubricant is pentaerythritol stearate.

3. The high-transmittance lens according to claim 1, characterized in that, The method for preparing the modified polymethyl methacrylate includes the following steps: S11. Methyl methacrylate and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole were added to a reaction vessel; toluene was then added; high-purity nitrogen gas was introduced to obtain a monomer mixture; S12. Under nitrogen protection, mercaptoethanol is added to the monomer mixture; then azobisisobutyronitrile is added and stirred; under nitrogen protection, the temperature is increased to react; stirring is maintained during the reaction; after the reaction is completed, the temperature is lowered to obtain a polymer solution; S13. Add the polymer solution to methanol and stir; filter and collect the precipitate; wash the precipitate with methanol; dry and pulverize the washed precipitate to obtain modified polymethyl methacrylate.

4. A high-transmittance lens according to claim 3, characterized in that, The mass ratio of methyl methacrylate to 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole is 93:7; the amount of azobisisobutyronitrile is 0.8% of the total mass of methyl methacrylate and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole; and the amount of mercaptoethanol is 1.5% of the total mass of methyl methacrylate and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole.

5. A high-transmittance lens according to claim 1, characterized in that, The method for preparing the modified polycarbonate includes the following steps: S21. Dry the low molecular weight polycarbonate to obtain dried polycarbonate; dry 3,5-di-tert-butyl-4-hydroxybenzoic acid to obtain dried 3,5-di-tert-butyl-4-hydroxybenzoic acid; dissolve the dried polycarbonate in dichloromethane to obtain a mixed solution; S22. Add dry 3,5-di-tert-butyl-4-hydroxybenzoic acid to the mixed solution, then add 4-dimethylaminopyridine, stir to dissolve, and finally add dicyclohexylcarbodiimide; under nitrogen protection, stir the reaction to obtain a suspension; S23. After the reaction is complete, filter the suspension; add the filtrate to methanol and stir; filter and collect the solid precipitate, wash with methanol; dry and pulverize the washed solid precipitate to obtain modified polycarbonate.

6. A high-transmittance lens according to claim 5, characterized in that, The number average molecular weight of the low molecular weight polycarbonate is 3000; the amount of 3,5-di-tert-butyl-4-hydroxybenzoic acid is 7.5% to 8.5% of the mass of the low molecular weight polycarbonate; the amount of 4-dimethylaminopyridine is 0.55% to 0.65% of the mass of the low molecular weight polycarbonate; and the amount of dicyclohexylcarbodiimide is 7.0% to 8.0% of the mass of the low molecular weight polycarbonate.

7. A high-transmittance lens according to claim 1, characterized in that, The preparation method of the modified polycarbonate-polymethyl methacrylate composite includes the following steps: S31. Modified polymethyl methacrylate and modified polycarbonate are added to a dry reaction vessel, and then anhydrous tetrahydrofuran is added. The mixture is stirred under nitrogen protection to obtain polymer mixed solution A. S32. Add dibutyltin dilaurate to polymer mixture solution A and stir under nitrogen protection to obtain polymer mixture solution B; separately dissolve isophorone diisocyanate in anhydrous tetrahydrofuran to obtain dilute solution A; under nitrogen protection and continuous stirring, slowly add dilute solution A dropwise to polymer mixture solution B; after the addition is complete, raise the temperature and stir the reaction under nitrogen protection to obtain polymer mixture solution C; S33. After cooling, slowly pour the polymer mixture C into a mixed solvent of hexane and diethyl ether while stirring, and filter to obtain flocculent solid A; wash flocculent solid A with hexane; dry and pulverize the washed flocculent solid A to obtain a modified polycarbonate-polymethyl methacrylate composite.

8. A high-transmittance lens according to claim 7, characterized in that, The mass ratio of modified polymethyl methacrylate to modified polycarbonate is 2:1; the amount of isophorone diisocyanate added accounts for 1.5% of the total mass of modified polymethyl methacrylate and modified polycarbonate.

9. A process for manufacturing a high-transmittance lens, applied to the manufacture of a high-transmittance lens as described in any one of claims 1 to 8, characterized in that, The preparation process includes: S1. Raw material drying: Dry the polycarbonate and the modified polycarbonate-polymethyl methacrylate composite separately; S2. Premixing: The dried polycarbonate, the dried modified polycarbonate-polymethyl methacrylate composite, the antioxidant, and the lubricant are sequentially added into a high-speed mixer and mixed to obtain a premix. S3. Melt blending and granulation: The premixed material is fed into a twin-screw extruder for granulation to obtain granules; S4. Injection Molding: The obtained granules are placed in an injection molding machine, melted, and injected into a lens mold. After cooling and molding, a lens with high light transmittance is obtained.

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